The present invention relates to a non-adhesive strain relief connector for a fiber optic cable. More particularly, the present invention relates a fiber optic cable that is disposed with in a metal sleeve, with the cable and sleeve being simultaneously compressed forming a long flat crimp connector having a width that is substantially greater than its height. The combination of the length and the width results in a large frictional surface between the sleeve and the fiber optic cable providing a strong, reliable connection.
Strain relief connectors for fiber optic cables are common in the connector industry. Conventional strain relief connectors have a sleeve surrounding a light transmitting optical fiber or a plurality of light transmitting optical fibers. The optical fibers are generally surrounded or covered and protected by a jacket or buffer material formed from a plastic. The sleeve and the fiber optic cable are then crimped using a crimping tool into a hexagonal or round shape.
Conventional crimping methods do not allow adequate lateral flow of the jacket material, in other words, the jacket material does not substantially flow in a direction perpendicular to the longitudinal axis of the crimp sleeve. A lack of lateral flow forces the buffer material to flow along the longitudinal axis of the crimp sleeve, producing longitudinal flow. Longitudinal flow places tension on the optical fiber, possibly causing damage to or failure of the optical fiber, or changing its optical characteristics.
In addition, conventional crimping methods have a crimp length that is short relative to the diameter of the jacket material. Generally, the length of the crimp is less than four times the buffer material diameter. This short length results in a small area of frictional contact between the inner surface of the crimp sleeve and the outer surface of the buffer material and may make failure of the connector more likely under tensile or thermal stress.
Examples of prior art fiber optic cable crimp connectors are disclosed in the following U.S. Pat. No. 3,655,275 to Seagraves; U.S. Pat. No. 4,738,504 to Jones; U.S. Pat. No. 5,140,662 to Kumar; U.S. Pat. No. 5,317,664 to Grabiec et al.; U.S. Pat. No. 5,418,874 to Carlisle et al.; U.S. Pat. No. 5,455,880 to Reid et al.
Thus, a continuing need exists for strain relief fiber optic connectors.
Accordingly an object of the present invention is to provide a strain relief connector for a fiber optic cable that has a relatively large frictional area between the inner surface of the crimp sleeve and the cover layer of the fiber optic cable for a strong reliable crimp connector.
Another object of the present invention is to provide a strain relief connector for a fiber optic cable that has a crimped configuration that allows for substantial lateral flow of the cover layer, putting substantially no longitudinal pressure or strain on the optical fiber.
Still another object of the present invention is to provide a strain relief connector for a fiber optic cable that has a crimp sleeve with a length that is long relative to the diameter of the cover layer, providing a large area of frictional engagement between the cover layer and crimp sleeve and the cover layer and optical fiber.
The foregoing objects are basically attained by providing a strain relief connector, comprising a securing member, a fiber optic cable having an optical fiber with an outer surface enclosed within a cover having an inner surface and a first outer diameter, and a sleeve surrounding the fiber optic cable and coupled to the securing member. The sleeve has a first inner diameter. The first inner diameter is substantially larger than the first outer diameter. A die compressed crimp portion of the sleeve and a compressed portion of the fiber optic cable, have widths substantially larger than heights thereof. The inner surface of the cover frictionally engages the outer surface of the optical fiber disposed therein.
Other objects, advantages and salient features of the invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments of the invention.